Impacts of Climate Change on Marine Foundation Species

Marine foundation species are the biotic basis for many of the world's coastal ecosystems, providing structural habitat, food, and protection for myriad plants and animals as well as many ecosystem services. However, climate change poses a significant threat to foundation species and the ecosystems they support. We review the impacts of climate change on common marine foundation species, including corals, kelps, seagrasses, salt marsh plants, mangroves, and bivalves. It is evident that marine foundation species have already been severely impacted by several climate change drivers, often through interactive effects with other human stressors, such as pollution, overfishing, and coastal development. Despite considerable variation in geographical, environmental, and ecological contexts, direct and indirect effects of gradual warming and subsequent heatwaves have emerged as the most pervasive drivers of observed impact and potent threat across all marine foundation species, but effects from sea level rise, ocean acidification, and increased storminess are expected to increase. Documented impacts include changes in the genetic structures, physiology, abundance, and distribution of the foundation species themselves and changes to their interactions with other species, with flow-on effects to associated communities, biodiversity, and ecosystem functioning. We discuss strategies to support marine foundation species into the Anthropocene, in order to increase their resilience and ensure the persistence of the ecosystem services they provide.

Molecular data reveals a new holomorphic marine fungus, Halobyssothecium estuariae, and the asexual morph of Keissleriella phragmiticola

This study introduces a novel holomorphic marine fungal species, Halobyssothecium estuariae (Lentitheciaceae, Pleosporales), from dead Phragmites communis. The new species has semi-immersed, subglobose or ellipsoidal, papillate, conical ascomata, clavate to subcylindrical, short pedicellate asci and 3-septate, fusoid to ellipsoidal ascospores with rounded ends, pale brown to dark brown central cells and hyaline end cells. The asexual morph has multiseptate, filiform, intercalary, catenate, branched chlamydospores that resemble Xylomyces. The asexual morph of Keissleriella phragmiticola based on combined LSU, SSU, ITS and TEF1 sequence analyses is reported. The role of molecular identification in delineating cryptic species are also discussed.